Fault Tree Analysis

1. FTA & FMEA Class
WorkSubmitted by
Ojes Sai Pogiri
K-5870

2. FTA
• Fault tree analysis (FTA) is a top-down, deductive failure analysis in which an undesired state of a
system is analyzed using Boolean logic to combine a series of lower-level events.
• FTA is used in the aerospace, nuclear power, chemical an process, pharmaceutical petrochemical and
other high-hazard industries; but is also used in fields as diverse as risk factor identification relating
to social service system failure.
• In aerospace, the more general term "system failure condition" is used for the "undesired state" / top
event of the fault tree.
• Fault tree analysis (FTA) was originally developed in 1962 at Bell Laboratories by H.A. Watson, under
a US air force Ballistics Systems Division contract to evaluate the Minutemal Intercontinental Ballistic
Missie (ICBM) Launch Control System.
• Event symbols are used for primary events and intermediate events. Primary events are not further
developed on the fault tree. Intermediate events are found at the output of a gate
• Gate symbols describe the relationship between input and output events

3. FMEA
• Failure Mode and Effects Analysis (FMEA) is a structured approach to discovering potential failures that
may exist within the design of a product or process
• FMEA is one of many tools used to discover failure at its earliest possible point in product or process
design. Discovering a failure early in Product Development (PD) using FMEA
• US Military at the end of the 1940s developed the technique to reduce sources of variation and
corresponding potential failures in the production of munitions – and it proved a highly effective tool
• By performing FMEA we have Design and Development ,Operations and Cost Benefits
• Types of FMEA:- Design , Process and System FMEA
• Steps in the FMEA
• Detecting the failure mode
• Finding Severity number (SEV), all the number are ranked from 1 to 10
• Probability of occurrence (occur)
• Detection number (DETEC)
• Risk Priority Number (SEV*Occur*DETEC) the smaller number is better for the any system
• Corrective actions.